For cosmetic or a variety of other reasons, people often wish to have a tattoo removed from their skin. Topical ointments are often used to try to cover the tattoo. However, because the pigment is an integral part of the cells in the dermis, removing the pigmentation is not an easy task and can only be effectively accomplished by destroying and replacing the cells containing the pigments. Known methods of eradicating tattoos include:                Dermabrasion, wherein skin is “sanded” (i.e., abraded) to remove the layers of skin containing the pigmentation;        Cryosurgery, wherein the pigmented area is frozen prior to its removal; and        Excision, wherein a dermatologic surgeon removes the pigmented skin with a scalpel and closes the wound with stitches. In some cases involving large areas of skin, a skin graft from another part of the body may be necessary.        
These methods are typically quite painful and frequently leave white spots and occasionally scars.
Lasers offer a more precise and generally less damaging alternative to the abovementioned methods. Each procedure is done as a single treatment, or in a series of treatments. Patients may or may not require topical or local anesthesia. Lasers remove the pigment by producing short pulses of intense light, which pass through the top layers of the skin and are then selectively absorbed by the pigment. The laser energy causes the pigment to be fragmented into smaller particles, which are then removed by the body's immune system. One of the problems with laser treatment, especially for the removal of tattoos, is that the absorption of the laser energy is color dependent and that a given laser can only be used to remove pigments in a particular color range. Moreover, there are side effects of laser procedures including occasional burning, scaring, hyper pigmentation (an abundance of color in the skin at the treatment site) and hypo pigmentation (the treated area lacks normal skin color).
A less traumatic method for removing pigmented areas of skin are described in International Patent Applications WO2004/107995, WO2005/020828, and WO2007/015232 by the Applicant of the present application.
The method described in these publications is based on the known fact that the tattoo pigments are mainly enclosed within cells located in the dermis layer of the skin. Therefore, as a first step, the tattooed area of skin is repeatedly punctured by an array of needles attached to a skin puncturing device similar to a tattooing machine in order to mechanically destroy the cells and release the pigments. After that the pigment fractions can rise to the surface through the pores created by the needles. The problem is that within a very short time period of several minutes the pores close, preventing all of the pigments from being removed. It is for this reason that in the second step of the method a pad containing a salt-based granulated paste is applied to the surface of the skin at the treated area for a limited period of time that is generally on the order of 20 minutes and does not exceed one hour. The salt-based granulated paste exerts a strong hygroscopic force to suck the intercellular fluid and debris including particles of pigment and fragments of the destroyed cells to the surface thereby taking advantage of the limited time frame available before the pores close to maximize the amount of the tattoo pigment that is removed from the dermis.
The first patent application describes the basic method and apparatus. The second application describes an apparatus for carrying out the method. This apparatus comprises a mediating member attached to a device similar to a conventional tattoo machine and a mediating member that is attached to the skin puncturing device. The mediating member is in contact with the skin and provides means for drawing off the cellular fluids and debris that rises to the skin surface at the site of the punctured skin and means for washing the needles and surface of the skin with a suitable liquid if desired. The third application describes a modification to the apparatus. In particular this application describes modifications to the skin puncturing device that allow an aqueous solution to flow onto the needles and the treated area of skin on each down stroke of the needles and to be sucked away on each upstroke of the needles. In this way the needles and the area of skin are continually rinsed with fresh solution to remove cellular fluid and debris including tattoo ink pigments that rise to the surface during the puncturing phase of the method and to insure that the needles are clean when they penetrate the skin.
It is a purpose of the present invention to provide new embodiments of the apparatus that, when used to carry out the basic method developed by the applicant, provides more complete eradication of tattoos than has been previously attainable.
Further purposes and advantages of this invention will appear as the description proceeds.